Man... I was just looking for user experiences on Monarchs as I'm looking into one on my latest rig and came across this thread. I usually don't get involved in these discussions, but there's enough confusing info this thread that I hope you don't mind me throwing in some detail. In no particular order:
Matching leverage ratios to the shock chart is generally a good idea because the range of adjustment is customized for the leverage rate. What this means is a 2:1 frame would require a much lower spring rate for the same rider weight as a frame that is say 3:1. Rebound adjusters have a finite amount of adjustment range and resolution. If you were to build a single damper with sufficient range to cover the big spread of spring rates possible switching from 2:1 to 3:1 AND different rider weights, you would either have a ridiculous number of turns on the knob or not fine enough changes from click to click.
Similar considerations are at work in compression in that a high leverage frame will overwhelm a comp circuit designed for a low leverage frame. In reverse, a low leverage frame with a hi lev shock will feel harsh.
From a shock maker's perspective, it would be more effective to target ranges of acceptable leverage for a shock and then specifically valve for that. All this assumes two things: 1) Rock Shox understood this and did significant testing to prove out their settings (I do not know if they did or not); and 2) You like their tuning philosophy.
That said, I basically agree with gvs_nz and usually prefer to run the lowest compression settings for plushness. I would like to slightly amend what he said about frame rates changing. Yes, some do change a lot (DW bikes), but others do not vary very much(single pivot, APP). Ultimately, only by experimenting will you figure out what you like in the overall feel. Some people prefer uber plush like a monster truck while others like a pronounced digressive curve like a sports car. By the way, thanks, gvs_nz for the info about the rebound tune on the low tune Monarch. :thumbsup:
Emulsification... well that's basically just gas getting entrained/dissolved/trapped in the oil. There's two ways I've seen this happen.
The first is the nitrogen (or air) in the IFP gets past the IFP. This can occur in a single catastrophic event (the origin of the term "blown" damper) which is immediately noticeable when the oil suddenly gets a huge bubble in it. Or it can happen slowly as small bubbles sneak past a compromised IFP seal. In either case, assuming you still have pressure in the IFP, repeated use of the shock will entrain the gas into the shock. The shock will make strange noises (cavitation) and have somewhat unpredictable performance as a result of the new compressibility of the oil.
The other thing that your shop may be calling emulsification is related to physical break down of the oil. Oil is not comprised of a homogenous molecule. In simple terms, it's combination of several different chemical chains. In general, longer chains are thicker viscosity and "heavier," while shorter chains are thinner and "lighter." The mixture of these molecules determines your overall viscosity and performance characteristics. Over time, as these molecules are sheared in the suspension valving, the lighter fractions break down and try to turn into gas phase. If your IFP pressure is still high and holding, these gases stay dissolved in the oil. When you release your IFP pressure, as your shop certainly did when they overhauled your shock, that gas comes out like opening a 2 liter bottle of Coke. From the mechanic's perspective, it's a blown shock, as you also get some weird performance and noise from cavitation. However, it's less bad than the first case as no significant changes to your IFP volume has occurred.
Hope that's helped.
